THAT CRAZY UNIVERSE
(originally run: April 1, 2005)
This happens to be the 500th edition of this
feature since it first began appearing in this newspaper in early 1995. Through
an interesting coincidence that involves the intricacies of our current
calendar system, this is also the first time that it has appeared on April 1,
i.e., April Fool's Day. Along these lines, perhaps it's appropriate to take a
look at some of the occasions when nature has had some fun with us as we
continue in our quest to understand it.
Almost everyone who systematically examines the nighttime
sky has had some ³April Fool's!² moments. For example, one night last summer
while this author was engaged in one of his observations, he happened to notice
a nearby star-like object just barely bright enough to be visible with the
unaided eye that wasn't shown on any star charts. The obvious explanation was
that this could be a nova, i.e., a star that explosively blows off its outer
atmosphere and briefly becomes bright, and this author went ahead and reported
the possible discovery of such an object. A nagging suspicion soon caused him
to check something, though, and he soon realized that he had in fact
³discovered² the planet Uranus, some 223 years after it had been found by the
British astronomer William Herschel.
Because so many of our observations take place right at
the limit of our equipment's capability, it is not surprising that some of the
reports that are made turn out to be false alarms. The attempts to detect planets
around other stars that were made during the middle decades of the 20th
Century serve as one such example, with the reports eventually being found to
be due to ³noise² in the data. (In one interesting incident, the report of a
planet was traced to the fact that a telescope's main lens had been taken out
for maintenance and then re-inserted, with just enough of a displacement to
mimic the positional shift a star would undergo if it had an orbiting planet.)
In 1991 a team of British astronomers announced that they
found evidence for a planet orbiting around a pulsar the shattered remains of
a star that has gone supernova, and one of the last places where one would
expect to find a planet. Their evidence consisted of periodic changes in the
arrival times of pulsed signals coming from the pulsar, and seemed to indicate
an accompanying planet with a six-month orbital period. After the intense
publicity that this report generated, the astronomers involved realized that
they had forgotten to include the Earth's non-circular orbit into their
calculations, and that the six-month period of the ³planet's² orbit was in fact
nothing more than a reflection of the Earth's own motion around the sun.
(Curiously, at about the same time that this error was
detected and announced, another astronomer reported the existence of a planet
around another pulsar. Not only has this object's existence been subsequently
verified, but three more planet-sized objects have since been detected around
this same pulsar.)
Sometimes erroneous reports of this nature have slipped
into this feature. For example, in late 1998 this feature reported on the
discovery of a possible ³rogue² planet, i.e., a planet without an accompanying
parent star. (If verified, this would have been the first direct detection of a
planet beyond our solar system.) Unfortunately, later observations have shown
that this object is nothing more remarkable than a dim background star.
One of the classic false alarms concerns the supernova
that appeared in the Large Magellanic Cloud (a satellite galaxy of the Milky
Way) in early 1987 the brightest supernova we've seen in 400 years. A
supernova of this type would be expected to leave a pulsar behind, and in early
1989 a team of astronomers announced their discovery of such an object,
rotating at the incredible rate of almost 2000 times per second. Further
observations failed to confirm the existence of this object, however, and a
year later the astronomers involved announced that the signals were caused by
interference from the television system used to control the telescope.
Sometimes, though, nature goes the other way, and gives
us something when we least expect it. One curious example took place late in
the 19th Century, when in 1895 the American astronomer Charles Perrine
discovered a comet that then disappeared behind the sun before reappearing in
the morning sky early the following year. A German astronomer named Lamp
recovered Perrine's comet, and sent a telegram across the Atlantic reporting
this fact; however, the transmission was garbled, and the position that was
received in America was several degrees away from the position that Lamp had
reported. Perrine, who had already recovered his comet, concluded that Lamp had
actually discovered a new one, and when he turned a telescope toward the
position in Lamp's telegram immediately saw a previously-unknown comet.
In the early 1960s two Bell Telephone Labs engineers,
Arno Penzias and Robert Wilson, detected some noise in a radio antenna that was
being used to send telephone calls to Earth-orbiting satellites. At first they
attributed the noise to nesting pigeons in the antenna and went to the trouble
of cleaning out all the bird droppings in the system, but the noise still
persisted; eventually, Penzias and Wilson realized that they were actually
detecting the so-called cosmic background radiation that is the afterglow of
the Big Bang explosion that started the universe. In 1978 Penzias and Wilson
were awarded the Nobel Prize in Physics for their discovery.
It all goes to show that the universe has ways of
throwing us curve balls at times, but if we nevertheless learn to accept that
universe on its terms, sometimes we'll be rewarded in ways we didn't expect. As
the late science and science fiction writer Isaac Asimov once phrased it, ³The
most exciting phrase to hear in science, the one that heralds new discoveries,
is not `Eureka!' (I found it!) but that's funny . . .'²
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